It is common to use an implanted catheter to repeatedly access the vascular system of a patient and with the catheter perform repeated therapeutic medical activity. Such therapeutic activity could include the intermittent or continuous infusion of medication and fluids, the periodic sampling of blood, or the continuous withdrawal and return of blood for processing outside of the body of the patient. The catheters used in these activities are referred to as vascular access catheters.
Before any therapeutic activity can actually commence, however, the vascular access catheter must be implanted in the body of the patient with the distal tip of the catheter residing at the location in the vascular system at which an intended therapeutic activity is appropriate. Typically, most of the length of an implanted vascular access catheter resides within blood vessels of the vascular system, extending from the distal tip of the catheter to a location in the vascular system at which the catheter, by traversing a puncture or incision formed through a wall of the blood vessel in which the catheter is disposed, enters into the surrounding subcutaneous tissue of the patient. The location at which this occurs is referred to as a venipuncture site. Venipuncture sites are classified on the basis of the position of a venipuncture site in relation to the center of the body of the patient. Central venipuncture sites are those that enter the vasculature through the jugular or subclavian veins. Peripheral venipuncture sites typically enter the basilic or cephalic veins of the upper or lower arm. The freedom to select among venipuncture sites is determined largely on catheter size and vein size. Vein size is dependent on patient size and on location within the body, with peripheral veins being smaller than central veins.
Proximal of the venipuncture site, the implanted catheter extends through the subcutaneous tissue of the patient to emerge through the skin at a location that is referred to as the skin exit site. Most skin exit sites are chosen as being locations at which the proximal end of the implanted catheter can be easily manipulated by medical personnel. Favored among such locations are the neck, the region about the collar bone or chest wall, the upper leg, the upper arm, and the forearm. Occasionally, the skin exit site is somewhat removed from the venipuncture site. Then a significant portion of the length of the implanted catheter must be embedded in the subcutaneous tissue of the patient in a surgically created tunnel that extends from the venipuncture site to the skin exit site. In all instances, a portion of the proximal end of an implanted catheter must remain outside of the body of the patient. It is this portion of an implanted catheter, from the proximal end thereof to the skin access site, that is referred to as the extracorporeal portion of the implanted catheter.
The extracorporeal portion of an implanted catheter must be capable of being selectively coupled to and uncoupled from the tubing and medical equipment outside the body of the patient that are required for therapeutic activity. Accordingly, the proximal end of virtually all vascular access catheters terminates in a catheter coupling hub that can be secured in fluid communication with such tubing and medical equipment, or can be capped, valved, or clamped closed between periods of actual use. Due to the variation in length of catheter that is required to traverse the subcutaneous and intravascular route from implanted tip location to skin exit site, it often becomes necessary to trim the catheter to an appropriate length. Traditionally, it is the distal end of the catheter that is trimmed as opposed to the proximal end for a number of reasons, including the desire to provide accurate positioning of a pre-connected proximal suture wing hub in a desired location near the venipuncture site. In particular, clinicians are increasingly showing a preference for a stepped-taper or reverse-taper of the hub to be inserted partially into the venipuncture site to affect tamponade and reduce site bleeding.
Trimming the catheter to an appropriate length is particularly advantageous with respect to peripherally inserted central catheters (PICCs) where precise central venous catheter tip placement at the right atrial (RA), superior vena cava (SVC) junction is imperative to prevent potential thrombosis, traumatic or functional complications. Many types of catheters, however, cannot be distally trimmed due to the special configuration thereof, including, for example, dual lumen catheters with a pre-staggered tip, soft tip catheters, catheters with valved distal ends, etc. In the case of such catheters, a pre-connected hub at the proximal end of the catheter cannot be accurately located at the venipuncture site and, consequently, some length of catheter extends therefrom. This excess catheter length often presents difficulty in dressing the catheter and exposes the catheter to potential damage. Moreover, it is not possible in the placement of catheters having preformed distal tips to achieve tamponade at the venipuncture site.
Whether or not the catheter has a preformed distal tip, it is advantageous to be able to trim a catheter at its proximal end prior to connection to a coupling hub or other extracorporeal medical equipment because proximal trimming enables physicians to keep inventory low (as several different catheter lengths are unnecessary) and each catheter placed can be customized to the exact length optimal for patient comfort and operability of the catheter. As a result, many types of connection systems have been proposed to couple a proximal end of a catheter to a medical device.
With particular reference to a catheter that has a been subcutaneously placed, in which an extracorporeal portion is to be connected to a coupling hub, systems such as that shown in FIG. 1 have been traditionally utilized. As shown, a catheter 20 is attached to a coupling hub 12 through three pre-assembled pieces. The proximal end of the catheter 20 is slid through strain relief sleeve 18, distal coupling 16 and compression sleeve 14. The proximal end of the catheter 20 is then slid over the cannula of coupling hub 12. Distal coupling 16 is snapped into coupling hub 12, exerting pressure against compression sleeve 14, which in turn retains catheter 20 on the cannula coupling hub 12. While such a connection system may be adequate for providing a secure connection, assembly can prove problematic due to the small size of the pieces involved as well as the extremely limited space with which the physician typically has to work. Moreover, the manufacture of several different pieces may lengthen the time to manufacture, as well as the cost associated therewith.
As mentioned above, in some instances it is preferable to partially insert a catheter hub into the venipuncture site. However, a system has not been previously proposed that will permit precise placement of the non-trimmed distal tip of the catheter subcutaneously while also providing the ability for the proximal hub to be partially inserted into the venipuncture site. Moreover, whereas prior art systems for proximally trimmable single lumen catheters have been proposed, such as depicted in FIG. 1, there has not to date been proposed a system for proximally trimmable externalized dual lumen catheters.
Accordingly, it is an object of the present invention to provide a catheter connector system, which safely and effectively connects a proximal end of a catheter to extracorporeal medical equipment, following placement of the distal end of the catheter in a patient. It is a further object of the present invention to provide a catheter connector system that permits venipuncture tamponade, that reduces assembly time of an associated suture wing, that improves robustness of the externalized catheter by eliminating unprotected catheter portions, that provides the functionality of a repair kit, and that provides a proximally trimmable design for a dual-lumen catheter.
Various other objectives and advantages of the present invention will become apparent to those skilled in the art as more detailed description is set forth below.